17.
Enclosure protection IP 68
Definition
According to EN 60 259, the conditions for meeting the requirements of
enclosure protection IP 68 are to be agreed between manufacturer and
user.
AUMA actuators and controls in enclosure protection IP 68 meet the
following requirements according to AUMA:
.
Duration of submersion in water max. 72 hours
.
Head of water max. 6 m
.
Up to 10 operations during submersion
.
Modulating duty is not possible during submersion
Enclosure protection IP 68 refers to the interior of the actuators (motor,
gearing, switch compartment, control, and terminal compartment).
For multi-turn actuators, the following has to be observed:
When using output drive types A and AF (stem nut), it cannot be prevented
that water enters the hollow shaft along the valve stem during submersion.
This leads to corrosion. The water also enters the thrust bearings of output
drive type A, causing corrosion and damage of the bearings. The output
drive types A and AF should therefore not be used.
Inspection
AUMA actuators and controls in enclosure protection IP 68 undergo a
routine testing for tightness in the factory.
Cable glands
.
For the entries of the motor and control cables, appropriate cable glands
in enclosure protection IP 68 must be used. The size of the cable glands
must be suitable for the outside diameter of the cables, refer to
recommendations of the cable gland manufacturers.
.
As standard, actuators and controls are delivered without cable glands.
For delivery, the threads are sealed with plugs in the factory.
.
When ordered, cable glands can also be supplied by AUMA at an
additional charge. For this, it is necessary to state the outside diameter of
the cables.
.
The cable glands must be sealed against the housing at the thread with an
O-ring.
.
It is recommended to additionally apply a liquid sealing material (Loctite or
similar).
Commissioning
When commissioning, the following should be observed:
.
Sealing faces of housing and covers must be clean.
.
O-rings of the covers must not be damaged.
.
A thin film of non-acidic grease should be applied to sealing faces.
.
Covers should be tightened evenly and firmly.
After submersion
.
Check actuator.
.
In case of ingress of water, dry actuator correctly and check for proper
function.
18.
Maintenance
After maintenance, check multi-turn actuator for damage to paint finish. If
damage to paint-finish has occurred after mounting, it has to be touched up
to avoid corrosion. Original paint in small quantities can be supplied by AUMA.
AUMA multi-turn actuators require very little maintenance.
Precondition for reliable service is correct commissioning.
24
Multi-turn actuators SAN 07.1 – SAN 25.1/SARN 07.1 – SARN 25.1
for valve automation in nuclear power plants
Operation instructions
